Apparatus for slow deposition of liquid



1934- T. F. CALLAHAN 1,970,688

APPARATUS FOR SLOW DEPOSITION OF LIQUID Filed May 9, 1932 fizz/62210," 4 fzirwlijil a llaaiz Patented Aug. 21, 1934 PATENT QFFIC'E .APPARATUS non sLovv DEPOSITION 7 LIQUID 1 1Timothy F. Callahan, Quincy, Mass. 3 f Application May 9,1932, Serial No. 610,293 5 Claims. (01. 221-67) This invention relates to improvements in apparatus for slow deposition of liquid, More particularly it provides an automatic liquid dropper, and means whereby theindividual drops, coming from a suitable liquid supply, occurat infrequent intervals.- For example, a single drop of liquid may be deposited at say eight minute intervals; and thesupply maybe such that the intermittent deposition can continue through long periods of time, such as'a month or three months, without need for replenishing the supply. The invention is useful'andeffective for handling all relatively free-flowing liquids, and may have a variety of applications. One particular utility is for depositing and maintaining a film of oil over the surface of water in pools or marshes which are known to be breeding beds for mosquitoes and other insect pests.

strenuous campaigns are waged each year in certain areas of this country, and elsewhere, to exterminate mosquitoes and, more especially, to prevent their ,multiplication during the warm summer months. These certain areas are peculiarly-prone to invasion by mosquitoes and,'un-

25' less preventive steps are taken, the extreme rapidity with which the pests breed and multiply, results in a very annoying, discomforting and un-' sanitary condition.

It is well known that bodies of stagnant water, such'as rain water in pools, and in catch basins, and even water in pools and marshes which may change with rise and fall of the tide, but which may stand for several hours at times of. low tide, release thousands of newly hatched mosquitoes daily during the warm weather. And it has be-' come well known that a film of oil spread over the surface of such breeding beds acts as a smothering blanket for exterminating newly born insects, and as a deterrent to use of the water as a breeding bed.

I Beneficial effects have been incident to the use of oilas above set forth. But'the applying and maintaining of an oil film over the water surfaces, bythe usual manual application and frequent replenishing, is expensive and not entirely satisfactory. It is expensive because of the almost constant attention needed to keep thewater surfaces covered with the film. And it has proven not wholly satisfactory because in many cases the water changes with rise and fall of the-tide, and it ispractically' impossible, 'by manual spraying, or the like, to keepthe water -surfaces completely blanketed. H

It is an object of the-invention to provide for deposition of liquid, from a suitable supply,-in infrequently occurring drops, with continuous but intermittent deposition throughout long periods of time.

Another object is to provide for having intervals of several minutes duration between successive drops. l

Still another object, in the use of the invention for extermination of insects, is to provide so that the oil treatment of insect-breeding bodies of water may be accomplished automaticallygeifectively and at relatively small expense.

It is, moreover, an important'feature that" the invention may be embodied in a portable apparatus which may be held as desired by a suitable suspension supportyor the invention may be in the nature of a permanent inter-connected system with multiple liquid droppers serving a substantial marshy area; or an-extensive body of water.

These objects and results may be attained by means of a dropper-nozzle having provision for restricted outflow of liquid, and providing also for infiow of air 'sufiicient to replace liquid which has flowed out from the nozzle. Strictly speaking, there is no flow-discharge at the nozzle, but rather the liquid forms at the end of the'nozzle in a succession of drops. This result is occasioned by the fact that the supply of liquid is held in an air-tight receptacle, and by further fact of the restricted character of the nozzle. Thus, in the absence of further features of the invention,

a. drop of liquid,'formingat the endof the nozzle, would completely seal the nozzle against inflow of air; and atmospheric pressure would hold the drop indefinitely. The invention, however, provides for the slow formation of the liquid in drops, and for admission of a little air through the nozzle after a dropiscompletely' formed. The nozzle may have two passages through it,'one for liquid outflow and the other for air inflow; or may have a single passage providing that the tip end of the nozzle is suitably formed, as will be hereinafter described.

In a preferred embodiment, the dropper nozzle may be connected directly to'a container capable of holding a suitable supply of liquid. And such a receptacle; which may be portable in nature, may be supported as desired, to provide a continuous but slowly intermittent deposition of liquid, throughout long periods of time, without attention. It is intended that the patent shall cover, by suitable expression in the appended claims, what'- ever features of'patentable novelty exist in the invention disclosed.

Inthe accompanying drawing: Figure l is an elevation, in medial section, of apparatus embodying features of the invention; and V Figures 2, 3 and 4 are elevations, in medial section showing modified forms of dropper-noz 1 "Referring to the drawing, the container 10 maybe considered representative of receptacles generally, whether portable, or permanently fixed A dropper-nozzle 18 may be attached to the neck 14 in any practicable way, as by threaded engagement therewith, as illustrated. And a gasket 20 may be employed to ensure an air-tight connection. The nozzle 18 has two passages 22, 24 through it, one for liquid outflow and the other for air inflow; and both of these passages are somewhat restricted'at' the extreme end of the nozzle.

Nozzle 18 may be formed as a single tube with interior dividing partition 26, as represented, or a 3 double tube formation will produce similar results.

In use, the container 10 may be filled or partly filled with liquid, which may be oil in the case of an insect exterminator. The dropper-nozzle then may be attached, and'the device be transported as desired, and ready for instant operation when inverted. Suitably held or supported at its destination thedropper-nozzle will drop the liquid with slowly intermittent action, the liquid flowing through passage 22. to formsuccessive drops at the end of the nozzle, and suflicient air being admitted into passage 24, as a bubble forms, to fill the space in container 10 which was vacated by the drop of liquid. The air admission, restricted by the passage inlet itself, is further restricted by the forming drop of liquid, and as a result, the development of each drop to the extent that gravity pulls it from the nozzle, takes a considerable time. Experiment has demonstrated that the successive drops may be eight or e'ven moreminutes apart. Consequently, with a supply container of suitable capacityjthe device can function throughout a month or several months without replenishing the supply, or giving it other attention.

I In the application of the invention for deposition of oil for exterminating insects, there are very definite advantages. It makes the oil treatment of breeding beds eflicientand practicably economical, whereas by prior manual methods,

I this treatment has not been entirely satisfactory,

and has been almost prohibitively expensive if carried to the desired extent. 7

In Fig. 2 of the drawing a somewhat modified form of dropper-nozzle is illustrated, but with the liquid passage ,30 extending beyond the air passage 32.. With this form-air is admitted more freely than in the form of Fig. 1, and the successive drops will be more frequent.

Fig. 3 shows a single passage dropper-nozzle with the end cut away on an incline with respect to the axis of he nozzle. In this form liquid forms in successive drops as inthe previous cases, but each drop as it forms runs to the extreme end 34 of the nozzle 36, thus permitting, air to enter at 38. i 1

i If desired two separate tubes may be employed as in Fig. 4, one for liquid outflow and the other for air inflow. In this caseboth tubes 40,42

extend through the cap. 44,:termin'ating interior-' 1 1y a little beyond the mouth ofthe receptacle,

and extending exteriorly any suitable distance, with the'air tube 42 preferably a little shorter than liquid tube 40. The operation of this form issimilar to. the others.

drop,

However, in Figure 4, there is represented a wire 46 in the liquid tube, and a wire 48 in the air tube. By this means the nozzle passages may be restricted as desired, by inserting wire of gage to suit the particular requirements. And the wires may be bent at either end to prevent their falling out. In this case the successive drops coming from the nozzle, run down the wire which projects from the liquid tube, and finally under the influence of gravity.

The wire for regulating the rate of deposition, although shown only in connection with Fig. 4,

may be employed in like manner in the other illustrated forms of the invention.

Iclaim as my invention:

1. Apparatus for slow deposition of liquid, comprising an aintight container for holding a supply of liquid, a tubular nozzle projecting from the container at 'a low down locationliaving its passage restricted to an extent whereby liquid encounters difficulty in passing therethrough, and reaches the nozzle end in the form of successive drops; and means at the end ofsaidnozzle ior admitting air into'the container'past a drop of liquid which may have formedon the end of said nozzle.

2. Apparatus for slow deposition of liquid, comprising an air-tight container for holding a supply of liquid; a tubular nozzle projecting from the container at a low down location, and having two parallel passages, each communicating with the interior ofthe container, and each open to atmosphere at the end of said nozzle; one said passage being. restricted to an extent whereby liquid encounters diiiiculty in passing therethrough, for slow feed of liquid in a succession of drops to the nozzle end, and the other constituting an air inlet past the liquid deposited at the nozzle end from the passage for liquid.

3. Apparatus for slow deposition of liquid, comprising anair-tight container forv holding a supply of liquid'and having a sediment-collecting bottom-wall portion; a tubular nozzle projectingout of said collecting portion of wall, and projecting inward an appreciable distance beyond said collecting portion of wall; and means at the end of the nozzle for simultaneous outflow of liquid and inflow of air; said nozzle having its passage restricted to an extent whereby liquid encounters difficulty in passing .therethrough. and reaches the nozzle end in the form of successive drops.

4. Apparatus for slow deposition of liquid, comprising an air-tight container having fixed interior dimensions, for holding a supply of liquid; a tubular nozzle projecting from the container at a low down location, the endof. said nozzle being cut back at an incline with respect to the axis of the nozzle to provide an approximately elliptical nozzle opening, thereby to unbalance the forces effective on a drop' of liquid atthe end of the nozzle and preventing liquid sealing of-the end of the nozzle,

5. Apparatus for slow deposition of Iiquid'comprising an air-tightcontainer-having fixed interior dimensions, for holding a supply of liquid;

restricting means extending down through and beyondthe nozzle.

4 CALLAHAN. 

